title: Optical imaging of somatosensory evoked potentials in the rat cerebral cortex after spinal cord injury.
abstract: Optical imaging techniques have made it possible to monitor neural activity and to determine its spatiotemporal patterns. Traumatic spinal cord injury (SCI) results in both the death of gray matter neurons and the disruption of ascending and descending white matter tracts at the injury site, leading to the loss of motor and sensory functions. In this study, we monitored and compared cortical responses to the stimulation of sensory tracts in normal control and spinal-cord-injured rats using an optical imaging technique based on a voltage-sensitive dye (VSD). The sciatic nerve was stimulated with a platinum bipolar electrode, and the exposed cortical surface was stained with Di-2-ANEPEQ. Optical signals were recorded from the cerebral cortex using the MiCAM02 optical imaging system. Characteristic spatiotemporal patterns were observed in response to electrical stimulation of the sciatic nerve in normal control rats. In spinal-cord-injured rats, the optical signals were dramatically reduced compared to those of normal rats. Four weeks after SCI, however, the activation area increased in the vicinity of the focal sensory area compared to that of the rats 1 week after SCI. These results suggest that optical imaging with VSD may be useful to map functional changes after SCI.
authors.affiliation: Department of Dental Hygiene, Division of Health Science, Dongseo University, Busan, Korea.
authors.forename: Kyung Hee
authors.initials: KH
authors.lastname: Lee
authors.forename: Un Jeng
authors.initials: UJ
authors.lastname: Kim
authors.forename: Yong Gou
authors.initials: YG
authors.lastname: Park
authors.forename: Ran
authors.initials: R
authors.lastname: Won
authors.forename: Hyejung
authors.initials: H
authors.lastname: Lee
authors.forename: Bae Hwan
authors.initials: BH
authors.lastname: Lee
mesh_terms: D000818:Animals; D001931:Brain Mapping / Q000379:methods*; D002540:Cerebral Cortex / Q000503:physiopathology*; D004558:Electric Stimulation; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D008297:Male; D009431:Neural Conduction / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013119:Spinal Cord Injuries / Q000503:physiopathology*; D056969:Voltage-Sensitive Dye Imaging / Q000379:methods*